Application filed August 11,1900. Serial to. 27,196. (Noniodeli) To all whom it may concern: Be it known that I, JOHN D. NICHOLSON, a citizen of the United States, and a resident of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a certain new and useful Improvement in Electrical Conductors, of which the following is a specification.

r This invention relates to a novel electrical re, conductor or wire; and it consists in a wire drawn or rolled from a compound ingotmade of two metals, one being copper and the other aluminium, substantially as hereinafter fully described and claimed.

r 5 In the drawing which forms partof this specification the figure is a transverse section of my compound wire.

Some of the more pertinent physical characteristics of aluminium and copper are as :0 follows:

The two metals readily-fuse together to form alloys of more orless value in the mechanical arts; but the important electric characteristics then no longer exist. The electric conductivity, for example, diminishes rapidly with the addition of copper, while the tensile strength may increase greatly.

I have found that a wire can be readily drawn from a compound ingot composed of Q the two metals poured or formed'se'parately,

' 'in some cases the core being of copper and the shell of aluminium, in other cases thereverse.

'45 In such a wire each metal preserves its own characteristics and both metals partake in the increase of tensile strength due to the operation of drawing. The conductivity of either remains intact. Byduly proportioning the two metals the resultant strength, conductiv- 5'0 ity, sectional area, or weight may be brought to any desired standard.

I prefer to make the compound wire with a. copper core and aluminium shell on account of the greatly-reduced liability to corrosion. In coupling such wires or making branch connections the difiiculty ordinarily found in soldering aluminium is not serious, as the copper part of the conductor can be readily soldered without seriously raising the resistance 6:: of the joint.

The particular method of forming the com pound ingot may vary, as that is not of the essence of my present invention. A simple way is by casting first acore of copper, it having the higher melting-point,and then while this is at or near the melting-point of alue minium casting the shell of the latter around such copper core, or the operation maybe reversed as to positions, the first cast, of copper, being the shell and the cast of aluminium being the core, or in some cases the hollow and solid ingots may be separately formed and consolidated by hydraulic or other pressure applied before or after cooling or while the core is cold and the shell still heated.

In referring to either of the two component parts of my new conductor I wish to say that they are supposed to be substantially pure; but the presence of slight admixtures of phos- 8c phorusor other well-known deoxidizing reagents is not objectionable, provided the individual characteristics of the two metals are substantially preserved. I

I claim as my invention- A compound electrical conductor composed of a core and a-shell of different metals drawn into wire, one metal being aluminium and the other copper.

Signed at the city of Belfast, Ireland, this 0 9th day of July, 1900. V